The present invention relates to a polymeric compound for photoresist, to a resin composition for photoresist containing the polymeric compound, and to a method of manufacturing a semiconductor. Such photoresists are for use in, for example, fine patterning of semiconductors.
Positive photoresists for use in manufacturing processes of semiconductors must concurrently have different characteristics such as a characteristic that exposed portions become soluble in alkali by light irradiation, adhesion to silicon wafers, plasma-etching resistance, and transparency to light used. The positive photoresists are generally used as a solution containing a base component polymer, a light-activatable acid generator, and several types of additives for controlling the above characteristics. It is very important for the base component polymer to have the above individual characteristics in balance in order to prepare an appropriate resist in accordance with its use.
The wavelength of a lithographic light source for use in the manufacture of semiconductors becomes shorter and shorter in recent years, and ArF excimer laser with a wavelength of 193 nm is promising as a next-generation light source. The use of a unit containing an alicyclic hydrocarbon skeleton has been proposed as a monomer unit for a resist polymer for use in the ArF excimer laser exposure system (e.g., Japanese Patent No. 2776273). Such alicyclic hydrocarbon skeletons are highly transparent with respect to light with the aforementioned wavelength and are resistant to etching. The use of a polymer having an adamantane skeleton as a resist polymer is also known, which adamantane skeleton exhibits especially high etching resistance among alicyclic hydrocarbon skeletons. However, such alicyclic hydrocarbon skeletons are highly hydrophobic and therefore exhibit low adhesion to substrates, although they have high etching resistance as mentioned above. To relieve this disadvantage, the aforementioned Japanese patent therefore proposes copolymers containing a highly hydrophilic monomer unit (an adhesion-imparting monomer unit) having, for example, a carboxyl group or a lactone ring. However, even these polymers do not always have sufficient adhesion to substrates. Additionally, the monomer units are not resistant to etching, and the etching resistance of the entire polymer becomes insufficient when the polymer contains such a sufficient amount of the monomer unit as to satisfy the required adhesion.
Japanese Unexamined Patent Application Publication No. 11-109632 makes an attempt to impart hydrophilicity to a polymer by introducing a hydroxyl group to an adamantane skeleton. However, if adhesion is improved by action of a hydroxyl-group-containing monomer unit alone, an alkali developer generally makes the resulting resist film swell, thus frequently inviting flexure or waviness in the resulting pattern.
Accordingly, an object of the present invention is to provide a polymeric compound for photoresist, which can satisfactorily adhere to substrates and can form fine patterns with high precision.
Another object of the present invention is to provide a polymeric compound for photoresist, which can satisfactorily adhere to substrates and has satisfactory transparency, alkali-solubility and etching resistance.
A further object of the present invention is to provide a resin composition for photoresist and a method of manufacturing a semiconductor, which can form fine patterns with high precision.
After intensive investigations to achieve the above objects, the present inventors have found that, when a polymer containing a monomer unit that has an alicyclic skeleton of a specific structure having a lactone ring is used as a photoresist resin, the resulting photoresist resin has markedly improved adhesion to substrates, is resistant to swelling in a developer and can form fine patterns with high precision. The present invention has been accomplished based on these findings.
Specifically, the present invention provides a polymeric compound for photoresist, which includes a monomer unit represented by following Formula (I): 
The polymeric compound may include the monomer unit represented by Formula (I) and at least one selected from monomer units represented by following Formulae (IIa) to (IIg): 
wherein R1 is a hydrogen atom or a methyl group; R2 and R3 are the same or different and are each a hydrocarbon group having from 1 to 8 carbon atoms; R4, R5 and R6 are the same or different and are each a hydrogen atom, a hydroxyl group or a methyl group; R7 and R8 are the same or different and are each a hydrogen atom, a hydroxyl group or a xe2x80x94COOR9 group, where R9 is a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or an 2-oxepanyl group; R10 and R11 are the same or different and are each a hydrogen atom, a hydroxyl group or an oxo group; R12 is a hydrocarbon group having a tertiary carbon atom at a bonding site with an oxygen atom indicated in the formula; R13, R14 and R15 are the same or different and are each hydrogen atom or a methyl group; R16 is a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or an 2-oxepanyl group; and n denotes an integer from 1 to 3.
The polymeric compound may further include at least one selected from monomer units represented by following Formulae (IIIa) to (IIIg): 
wherein R1 is a hydrogen atom or a methyl group; R17 and R18 are the same or different and are each a hydrogen atom, a hydroxyl group or a carboxyl group; R19 is a hydroxyl group, an oxo group or a carboxyl group; R20, R21, R22, R23 and R24 are the same or different and are each a hydrogen atom or a methyl group; R25 is a hydrogen atom or a methyl group; R26 is a tricyclo[5.2.1.02,6]decylmethyl group, a tetracyclo[4.4.0.12,5.17,10] dodecylmethyl group, a norbornyl group, an isobornyl group or a 2-norbornylmethyl group; and R27 is a substituent of R26 and is a hydrogen atom, a hydroxyl group, a hydroxymethyl group, a carboxyl group or a xe2x80x94COOR28 group, where R28 is a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or an 2-oxepanyl group.
The present invention further provides a resin composition for photoresist, which includes the polymeric compound for photoresist and a light-activatable acid generator. In addition, the present invention provides a method of manufacturing a semiconductor, which method includes the steps of applying the resin composition for photoresist onto a base or substrate to thereby form a resist film, and subjecting the resist film to exposure and development to thereby produce a pattern.
In the present description, the terms xe2x80x9cacrylicxe2x80x9d and xe2x80x9cmethacrylicxe2x80x9d may be generically referred to as xe2x80x9c(meth) acrylicxe2x80x9d, and the terms xe2x80x9cacryloylxe2x80x9d and xe2x80x9cmethacryloylxe2x80x9d may be generically referred to as xe2x80x9c(meth)acryloylxe2x80x9d.
Polymeric compounds for photoresist of the present invention comprise the monomer unit (constitutional repeating unit) represented by Formula (I) (hereinafter referred to as xe2x80x9cMonomer Unit 1xe2x80x9d). Monomer Unit 1 has a highly hydrophilic lactone ring and improves adhesion to substrate to thereby serve as a unit for imparting adhesion. It also has an alicyclic carbon ring (a norbornane ring), has the function of improving etching resistance and is resistant to swelling in an alkali developer. By using appropriate polymerizable monomers having the function of being soluble in alkali, the function of being resistant to etching, and other functions as comonomers in production of polymers, the resulting polymers have necessary functions as resists. Such polymers containing Monomer Unit 1 can be advantageously used as photoresist resins.
A polymeric compound as a preferred embodiment of the present invention includes the monomer unit represented by Formula (I) and at least one monomer unit (a constitutional repeating unit) (hereinafter referred to as xe2x80x9cMonomer Unit 2xe2x80x9d) selected from those represented by Formulae (IIa) to (IIg). In the monomer unit represented by Formula (IIa), an acid causes a moiety containing an adamantane skeleton to eliminate from a carboxylic acid moiety combined with a principle chain to thereby form a free carboxyl group. In the monomer unit represented by Formula (IIb), a carboxyl group is combined with the adamantane skeleton and is protected with a protective group, and an acid causes the carboxyl group to deprotect to thereby form a free carboxyl group. In the monomer unit represented by Formula (IIc), an acid causes an adamantane skeleton to eliminate from a carboxylic acid moiety combined with a principle chain to thereby form a free carboxyl group. Additionally, in the monomer units represented by Formulae (IId), (IIe), (IIf) and (IIg), an acid causes a carboxylic ester moiety to decompose and eliminate to thereby form a free carboxyl group. Accordingly, Monomer Unit 2 acts as an alkali-soluble unit that makes the resulting resin soluble in development with an alkali.
The monomer units represented by Formulae (IIa), (IIb), (IIc) and (IIg) each have an alicyclic carbon skeleton, have satisfactory transparency and are very highly resistant to etching. Monomer units of Formula (IIa) where at least one of R4 to R6 is a hydroxyl group, and monomer units represented by Formula (IIf) are highly hydrophilic and also have the function of adhering.
In Formula (IIa), hydrocarbons each having from 1 to 8 carbon atoms in R2 and R3 include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, pentyl, isopentyl, 1-methylbutyl, 1-ethylpropyl, hexyl, isohexyl, 1-methylpentyl, 1-ethylbutyl, heptyl, 1-methylhexyl, octyl, 1-methylheptyl and other C1-C8 alkyl groups; cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and other C3-C8 cycloalkyl groups; and phenyl group. Among these groups, methyl, ethyl, isopropyl and other C1-C3 alkyl groups are preferred.
In Formula (IId), the xe2x80x9chydrocarbon group having a tertiary carbon atom at a bonding site with an oxygen atom indicated in the formulaxe2x80x9d in R12 includes, but is not limited to, t-butyl group and t-amyl group.
The invented polymeric compounds for photoresist may further comprise at least one monomer unit (a constitutional repeating unit) (hereinafter referred to as xe2x80x9cMonomer Unit 3xe2x80x9d) selected from monomer units represented by Formulae (IIIa) to (IIIg), in addition to Monomer Unit 1 or to Monomer Units 1 and 2.
The monomer unit represented by Formula (IIIa) has a highly hydrophilic group (a hydroxyl group, carboxyl group or oxo group) combined with an adamantane skeleton and therefore plays a role of improving adhesion to substrates. Additionally, the monomer units represented by Formulae (IIIa), (IIIc), (IIId) and (IIIg) each have an alicyclic carbon skeleton and are conductive to the improvement in, for example, transparency and etching resistance. The monomer unit represented by Formula (IIIb) having a lactone skeleton and the monomer units represented by Formulae (IIIe) and (IIIf) each have a hydrophilic group and have the function of imparting adhesion. As thus described, these monomer units can impart various functions based on the structures thereof to polymers, and the resulting polymers comprising each of the monomer units can have finely controlled well-balanced characteristics required as resist resins depending on the applications thereof. To control the aforementioned characteristics, the invented polymeric compounds for photoresist may further comprise additional monomer units according to necessity in addition to the aforementioned monomer units.
In the invented polymeric compounds for photoresist, the content of Monomer Unit 1 is, for example, from about 1% to about 90% by mole, preferably from about 3% to about 60% by mole, and more preferably from about 5% to about 40% by mole, relative to the total monomer units constituting the polymers. Preferred polymeric compounds comprise from about 10% to about 90% by mole (e.g., from about 20% to about 80% by mole), and specifically from about 30% to about 70% by mole of Monomer Unit 2 relative to the total monomer units constituting the polymers. The content of Monomer Unit 3 in polymers containing the Monomer Unit 3, if any, is from about 1% to about 70% by mole, preferably from about 3% to about 60% by mole, and more preferably from about 5% to about 50% by mole, relative to the total monomer units constituting the polymers.
Of the combinations of the individual monomer units in the invented polymeric compounds, specifically preferred combinations are as follows:
(1) a combination of the monomer unit of Formula (I) and at least one selected from monomer units of Formulae (IIa) to (IIg);
(2) a combination of the monomer unit of Formula (I), at least one selected from monomer units of Formulae (IIa) to (IIg) and at least one selected from monomer units of Formulae (IIIa) to (IIIg) [especially, at least one selected from monomer units of Formulae (IIIa), (IIIf) and (IIIg)]; and
(3) a combination of the monomer unit of Formula (I) and at least one selected from monomer units of Formulae (IIIa) to (IIIg) [especially, at least one selected from monomer units of Formulae (IIIa), (IIIf) and (IIIg)].
In the preferred polymeric compounds of the present invention, the total content of monomer units each having an alicyclic skeleton [of Formulae (I), (IIa), (IIb), (IIc), (IIg), (IIIa), (IIIc), (IIId) and (IIIg)] is, for example, from about 50% to about 95% by weight, and specifically from about 60% to about 85% by weight, relative to the total monomer units constituting the polymers. These polymeric compounds are specifically satisfactorily resistant to etching.
The invented polymeric compounds each have a weight average molecular weight (Mw) of, for example, from about 5000 to about 50000 and preferably from about 7000 to about 20000, and a molecular weight distribution (Mw/Mn) of, for example, from about 1.8 to about 3.5. The figure Mn indicates a number average molecular weight (in terms of polystyrene).
Each of the monomer units represented by Formulae (I), (IIg), (IIIf) and (IIIg) can be formed by subjecting a corresponding ethylenically unsaturated compound as a (co-)monomer to polymerization. Likewise, each of the monomer units represented by Formulae (IIa) to (IIf) and (IIIa) to (IIIe) can be formed by subjecting a corresponding (meth)acrylic acid or its ester as a (co-)monomer to polymerization. Polymerization can be performed by conventional techniques for use in the production of acrylic polymers or polyolefinic polymers.
Monomer Unit of Formula (I)
A monomer corresponding to the monomer unit of Formula (I) is represented by following Formula (1): 
There are stereoisomers in this compound (bicyclo [2.2.1] hept-5-ene-2-hydroxymethyl-3-carboxylic acid lactone) [1-1]. Each of these stereoisomers can be used alone or in combination. This compound can be obtained, for example, by a Diels-Alder reaction between cyclopentadiene and 2,5-dihydrofuran-2-one.
Monomer Unit of Formula (IIa)
Monomers corresponding to the monomer units of Formula (IIa) are represented by following Formula (2a): 
wherein R1 is a hydrogen atom or a methyl group; R2 and R3 are the same or different and are each a hydrocarbon group having from 1 to 8 carbon atoms; R4, R5 and R6 are the same or different and are each a hydrogen atom, a hydroxyl group or a methyl group,
of which typical examples are the following compounds:
[2-1] 1-(1-(meth)acryloyloxy-1-methylethyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90R3xe2x95x90CH3, R4xe2x95x90R5xe2x95x90R6xe2x95x90H);
[2-2] 1-hydroxy-3-(1-(meth)acryloyloxy-1-methylethyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90R3xe2x95x90CH3, R4xe2x95x90OH, R5xe2x95x90R6xe2x95x90H);
[2-3] 1-(1-ethyl-1-(meth)acryloyloxypropyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90R3xe2x95x90CH2CH3, R4xe2x95x90R5xe2x95x90R6xe2x95x90H);
[2-4] 1-hydroxy-3-(1-ethyl-1-(meth)acryloyloxypropyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90R3xe2x95x90CH2CH3, R4xe2x95x90OH, R5xe2x95x90R6xe2x95x90H);
[2-5] 1-(1-(meth)acryloyloxy-1-methylpropyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90CH3, R3xe2x95x90CH2CH3, R4xe2x95x90R5xe2x95x90R6xe2x95x90H);
[2-6] 1-hydroxy-3-(1-(meth)acryloyloxy-1-methylpropyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90CH3, R3xe2x95x90CH2CH3, R4xe2x95x90OH, R5xe2x95x90R6xe2x95x90H);
[2-7] 1-(1-(meth)acryloyloxy-1,2-dimethylpropyl)adamantane (R1xe2x95x90H or CH3, R2xe2x95x90CH3, R3xe2x95x90CH (CH3)2, R4xe2x95x90R5xe2x95x90R6xe2x95x90H);
[2-8] 1-hydroxy-3-(1-(meth)acryloyloxy-1,2-dimethylpropyl)adaman tane (R1xe2x95x90H or CH3, R2xe2x95x90CH3, R3xe2x95x90CH2(CH3)2, R4xe2x95x90OH, R5xe2x95x90R6xe2x95x90H);
[2-9]1,3-dihydroxy-5-(1-(meth)acryloyloxy-1-methylethyl)adamant ane (R1xe2x95x90H or CH3, R2 xe2x95x90R3xe2x95x90CH3, R4xe2x95x90R5xe2x95x90OH, R6xe2x95x90H);
[2-10] 1-(1-ethyl-1-(meth)acryloyloxypropyl)-3,5-dihydroxyadamant ane (R1xe2x95x90H or CH3, R2xe2x95x90R3xe2x95x90CH2CH3, R4xe2x95x90R5xe2x95x90OH, R6xe2x95x90H);
[2-11] 1,3-dihydroxy-5-(1-(meth)acryloyloxy-1-methylpropyl)adaman tane (R1xe2x95x90H or CH3, R2xe2x95x90CH3, R3xe2x95x90CH2CH3, R4xe2x95x90R5xe2x95x90OH, R6xe2x95x90H); and
[2-12] 1,3-dihydroxy-5-(1-(meth)acryloyloxy-1,2-dimethylpropyl)ad amantane (R1xe2x95x90H or CH3, R2xe2x95x90CH3, R3xe2x95x90CH(CH3)2, R4xe2x95x90R5xe2x95x90OH, R6xe2x95x90H).
The compounds represented by Formula (2a) can be obtained, for example, in accordance with the following reaction process chart: 
wherein X is a halogen atom; Rx is a halogen atom, a hydroxyl group, an alkoxy group or an alkenyloxy group; and R1, R2, R3, R4, R5 and R6 have the same meanings as defined above.
Of adamantane derivatives (4) for use as raw materials in this reaction process chart, a compound in which any of R4 to R6 is a hydroxyl group can be obtained by introducing a hydroxyl group into an adamantane ring. For example, a hydroxyl group can be introduced into the adamantane ring by a process in which an adamantane compound is brought into contact with oxygen in the presence of a N-hydroxyimide catalyst such as N-hydroxyphthalimide and, where necessary, a metallic promoter (co-catalyst) such as a cobalt compound (e.g., cobalt acetate or acetylacetonatocobalt). In this process, the amount of the N-hydroxyimide catalyst is, for example, from about 0.0001 to about 1 mole and preferably from about 0.001 to about 0.5 mole, relative to 1 mole of the adamantane compound. The amount of the metallic promoter is, for example, from about 0.0001 to about 0.7 mole and preferably from about 0.001 to about 0.5 mole, relative to 1 mole of the adamantane compound. Oxygen is often used in excess to the adamantane compound. A reaction is performed, for example, in a solvent at a temperature of from about 0xc2x0 C. to about 200xc2x0 C. and preferably from about 30xc2x0 C. to about 150xc2x0 C. at atmospheric pressure or under a pressure (under a load). Such solvents include, for example, acetic acid and other organic acids, acetonitrile and other nitrites, and dichloroethane and other halogenated hydrocarbons. A plurality of hydroxyl groups can be introduced into the adamantane ring by appropriately selecting reaction conditions.
A reaction of the adamantane derivative (4) with a 1,2-dicarbonyl compound (e.g., biacetyl) (5) and oxygen can be performed in the presence of a metallic compound such as a cobalt compound such as cobalt acetate or acetylacetonatocobalt and/or an N-hydroxyimide catalyst such as N-hydroxyphthalimide. The amount of the 1,2-dicarbonyl compound (5) is 1 mole or more (e.g., from about 1 to about 50 moles), preferably from about 1.5 to about 20 moles and more preferably from about 3 to about 10 moles, relative to 1 mole of the adamantane derivative (4). The amount of the metallic compound is, for example, from about 0.0001 to about 0.1 mole relative to 1 mole of the adamantane derivative (4). The amount of the N-hydroxyimide catalyst is, for example, from about 0.001 to about 0.7 mole relative to 1 mole of the adamantane derivative (4). Oxygen is often used in excess to the adamantane derivative (4). The reaction is generally performed in an organic solvent. Such organic solvents include, but are not limited to, acetic acid and other organic acids, benzonitrile and other nitrites, and trifluoromethylbenzene and other halogenated hydrocarbons. The reaction is performed at a temperature of, for example, from about 30xc2x0 C. to about 250xc2x0 C. and preferably from about 40xc2x0 C. to about 200xc2x0 C. at atmospheric pressure or under a pressure (under a load).
A reaction between an acyladamantane derivative (6) thus obtained and a Grignard reagent (7) can be performed in a similar manner to a conventional Grignard reaction. The amount of the Grignard reagent (7) is, for example, from about 0.7 to about 3 moles and preferably from about 0.9 to about 1.5 moles, relative to 1 mole of the acyladamantane derivative (6). When the acyladamantane derivative (6) has hydroxyl group(s) on the adamantane ring, the amount of the Grignard reagent is increased depending on the number thereof. The reaction is performed in, for example, an ether such as diethyl ether or tetrahydrofuran. A reaction temperature is, for example, from about 0xc2x0 C. to about 150xc2x0 C. and preferably from about 20xc2x0 C. to about 100xc2x0 C.
A conventional process using an acid catalyst or a transesterification catalyst can perform a reaction (an esterification reaction) between an adamantanemethanol derivative (8) formed by the above reaction and a (meth)acrylic acid or its derivative (9). The compounds represented by Formula (2a) can be efficiently obtained under mild conditions by subjecting the adamantanemethanol derivative (8) to a reaction (a transesterification reaction) with an alkenyl (meth) acrylate such as vinyl (meth) acrylate or 2-propenyl (meth) acrylate in the presence of a catalyst of a Group 3 element compound of the Periodic Table of Elements (e.g., samarium acetate, samarium trifluoromethanesulfonate, samarium complexes, and other samarium compounds). In this procedure, the amount of the alkenyl (meth)acrylate is, for example, from about 0.8 to about 5 moles and preferably from about 1 to about 1.5 moles relative to 1 mole of the adamantanemethanol derivative (8). The amount of the Group 3 element compound catalyst of the Periodic Table of Elements is, for example, from about 0.001 to about 1 mole and preferably from about 0.01 to about 0.25 mole relative to 1 mole of the adamantanemethanol derivative (8). This reaction is performed in a solvent inert toward the reaction at a temperature of, for example, from about 0xc2x0 C. to about 150xc2x0 C. and preferably from about 25xc2x0 C. to about 120xc2x0 C.
Of the compounds represented by Formula (2a), a compound in which R2 and R3 are the same groups can be obtained, for example, in accordance with the following reaction process chart: 
wherein Ry is a hydrocarbon group; and X, R1, R2, R3, R4, R5, R6 and Rx have the same meanings as defined above.
The hydrocarbon group in Ry includes, but is not limited to, methyl, ethyl, propyl, isopropyl and other C1-C6 aliphatic hydrocarbon groups; and phenyl group.
An adamantanecarboxylic acid derivative (10) for use as a raw material in the above reaction process chart can be produced by introducing a carboxyl group into the adamantane ring of an adamantane compound. For example, a carboxyl group can be introduced into the adamantane ring of the adamantane compound by a process in which the adamantane compound is brought into contact with carbon monoxide and oxygen in the presence of a N-hydroxyimide catalyst such as N-hydroxyphthalimide and, where necessary, a metallic promoter (co-catalyst) such as a cobalt compound (e.g., cobalt acetate or acetylacetonatocobalt). In the carboxylation reaction, the amount of the N-hydroxyimide catalyst is, for example, from about 0.0001 to about 1 mole and preferably from about 0.001 to about 0.5 mole relative to 1 mole of the adamantane compound. The amount of the metallic promoter is, for example, from about 0.0001 to about 0.7 mole and preferably from about 0.001 to about 0.5 mole relative to 1 mole of the adamantane compound. The amounts of carbon monoxide and oxygen are, for example, 1 mole or more and 0.5 mole or more, respectively, relative to 1 mole of the adamantane compound. The ratio of carbon monoxide to oxygen is, for example, such that the former/the latter (by mole) is from about 1/99 to about 99/1 and preferably from about 50/50 to about 95/5. The carboxylation reaction is performed, for example, in a solvent at a temperature of from about 0xc2x0 C. to about 200xc2x0 C. and preferably from about 10xc2x0 C. to about 150xc2x0 C. at atmospheric pressure or under a pressure (under a load). Such solvents include, for example, acetic acid and other organic acids, acetonitrile and other nitrites, and dichloroethane and other halogenated hydrocarbons. A plurality of carboxyl groups can be introduced into the adamantane ring by appropriately selecting reaction conditions.
A reaction between the adamantanecarboxylic acid derivative (10) and a hydroxy compound (11) can be performed, for example, in accordance with a conventional esterification process using an acid catalyst.
A reaction between an adamantanecarboxylic ester represented by Formula (12) and a Grignard reagent (7) is generally performed in a solvent inert toward the reaction, such as diethyl ether, tetrahydrofuran and other ethers. A reaction temperature is, for example, from about 0xc2x0 C. to about 100xc2x0 C. and preferably from about 10xc2x0 C. to about 40xc2x0 C. The amount of the Grignard reagent (7) is, for example, from about 2 to about 4 equivalents relative to the adamantanecarboxylic ester (12).
A reaction (an esterification reaction) between an adamantanemethanol derivative (8a) and the (meth) acrylic acid or its derivative (9) can be performed in a similar manner to the reaction between the compound represented by Formula (8) and the (meth)acrylic acid or its derivative (9). Of the compounds represented by Formula (2a), a compound (2axe2x80x2) in which R2 and R3 are the same hydrocarbon group (e.g., R2xe2x95x90R3=ethyl group) can be easily prepared in this manner.
Monomer Unit of Formula (IIb)
Monomers corresponding to the monomer units of Formula (IIb) are represented by following Formula (2b): 
wherein R1 is a hydrogen atom or a methyl group; R7 and R8 are the same or different and are each a hydrogen atom, a hydroxyl group or a xe2x80x94COOR9 group, where R9 is a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or an 2-oxepanyl group,
of which typical examples are the following compounds:
[2-13] 1-t-butoxycarbonyl-3-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R7xe2x95x90R8xe2x95x90H, R9=t-butyl group);
[2-14] 1,3-bis(t-butoxycarbonyl)-5-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R7=t-butoxycarbonyl group, R8xe2x95x90H, R9=t-butyl group);
[2-15] 1-t-butoxycarbonyl-3-hydroxy-5-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R7xe2x95x90OH, R8xe2x95x90H, R9=t-butyl group);
[2-16] 1-(2-tetrahydropyranyloxycarbonyl)-3-(meth)acryloyloxyadam antane (R1xe2x95x90H or CH3, R7xe2x95x90R8xe2x95x90H, R9=2-tetrahydropyranyl group);
[2-17] 1,3-bis(2-tetrahydropyranyloxycarbonyl)-5-(meth)acryloylox yadamantane (R1xe2x95x90H or CH3, R7=2-tetrahydropyranyloxycarbonyl group, R8xe2x95x90H, R9=2-tetrahydropyranyl group); and
[2-18] 1-hydroxy-3-(2-tetrahydropyranyloxycarbonyl)-5-(meth)acryl oyloxyadamantane (R1xe2x95x90H or CH3, R7xe2x95x90OH, R8xe2x95x90H, R9=2-tetrahydropyranyl group).
The compounds represented by Formula (2b) can be obtained, for example, in accordance with the following reaction process chart: 
wherein Rx, R1, R7, R8 and R9 have the same meanings as defined above.
In the reaction process chart, a conventional process can convert a carboxyadamantanol derivative (13) into an 1-adamantanol derivative (14) (protection of a carboxyl group). Such conventional processes include a process in which the carboxyadamantanol derivative (13) is allowed to react with isobutylene, dihydrofuran or dihydropyran.
The carboxyadamantanol derivative (13) for use as a raw material in this procedure can be obtained by introducing a hydroxyl group and carboxyl group into the adamantane ring of an adamantane compound. The introduction of a hydroxyl group and carboxyl group into the adamantane ring can be performed in the same manner as above.
A reaction (an esterification reaction) between the 1-adamantanol derivative (14) and the (meth)acrylic acid or its derivative (9) can be performed in a similar manner to the reaction between the compound represented by Formula (8) and the (meth)acrylic acid or its derivative (9).
Monomer Unit of Formula (IIc)
Monomers corresponding to the monomer units of Formula (IIc) are represented by the following Formula (2c): 
wherein R1 is a hydrogen atom or a methyl group; and R10 and R11 are the same or different and are each a hydrogen atom, a hydroxyl group or an oxo group,
of which typical examples are the following compounds:
[2-19] 2-(meth)acryloyloxy-2-methyladamantane (R1xe2x95x90H or CH3, R10xe2x95x90R11xe2x95x90H);
[2-20] 1-hydroxy-2-(meth)acryloyloxy-2-methyladamantane (R1xe2x95x90H or CH3, R10=1-OH, R11xe2x95x90H)
[2-21] 5-hydroxy-2-(meth)acryloyloxy-2-methyladamantane (R1xe2x95x90H or CH3, R10=5-OH, R11xe2x95x90H);
[2-22] 1,3-dihydroxy-2-(meth)acryloyloxy-2-methyladamantane (R1xe2x95x90H or CH3, R10=1-OH, R11=3-OH);
[2-23] 1,5-dihydroxy-2-(meth)acryloyloxy-2-methyladamantane (R1xe2x95x90H or CH3, R10=1-OH, R11=5-OH); and
[2-24] 1,3-dihydroxy-6-(meth)acryloyloxy-6-methyladamantane (R1xe2x95x90H or CH3, R10=1-OH, R11=3-OH).
The compounds represented by Formula (2c) can be obtained, for example, in accordance with the following reaction process chart: 
wherein X, R1, R10, R11 and Rx have the same meanings as defined above.
In this reaction process chart, a reaction between an adamantanone derivative (15) and a Grignard reagent (16) can be performed in accordance with a conventional Grignard reaction. The amount of the Grignard reagent (16) is, for example, from about 0.7 to about 3 moles and preferably from about 0.9 to about 1.5 moles relative to 1 mole of the adamantanone derivative (15). When the adamantanone derivative (15) has hydroxyl group(s) on the adamantane ring, the amount of the Grignard reagent is increased depending on the number thereof. The reaction is performed in a solvent inert toward the reaction, such as diethyl ether, tetrahydrofuran and other ethers. A reaction temperature is, for example, from about 0xc2x0 C. to about 150xc2x0 C. and preferably from about 20xc2x0 C. to about 100xc2x0 C.
The above-prepared 2-adamantanol derivative (17) is subjected to a reaction (an esterification reaction) with the (meth)acrylic acid or its derivative (9) to thereby yield a compound represented by Formula (2c). The esterification reaction can be performed in a similar manner to the reaction between the compound of Formula (8) and the (meth) acrylic acid or its derivative (9).
Of the adamantanone derivatives (15) for use as a raw material in the above process, a compound having a hydroxyl group on the adamantane ring can be produced in the following manner. Specifically, a 2-adamantanone is brought into contact with oxygen in the presence of a N-hydroxyimide catalyst such as N-hydroxyphthalimide, and where necessary, a metallic promoter such as a cobalt compound, a manganese compound or a vanadium compound to thereby introduce a hydroxyl group into the adamantane ring. In this process, the amount of the N-hydroxyimide catalyst is, for example, from about 0.0001 to about 1 mole and preferably from about 0.001 to about 0.5 mole relative to 1 mole of the 2-adamantanone. The amount of the metallic promoter is, for example, from about 0.0001 to about 0.7 mole and preferably from about 0.001 to about 0.5 mole relative to 1 mole of the 2-adamantanone. Oxygen is often used in excess to the 2-adamantanone. The reaction is performed in a solvent at a temperature of from about 0xc2x0 C. to about 200xc2x0 C. and preferably from about 30xc2x0 C. to about 150xc2x0 C. at atmospheric pressure or under a pressure (under a load). Such solvents include, for example, acetic acid and other organic acids, acetonitrile and other nitrites, and dichloroethane and other halogenated hydrocarbons.
Of the adamantanone derivatives (15), a compound having a hydroxyl group on the adamantane ring can also be produced by allowing an adamantane to react with oxygen in the presence of the N-hydroxyimide catalyst, a strong acid (e.g., a hydrogen halide or sulfuric acid), and where necessary, the metallic promoter. The amount of the strong acid is, for example, from about 0.00001 to about 1 mole and preferably from about 0.0005 to about 0.7 mole relative to 1 mole of the adamantane. The other reaction conditions are similar to those in the reaction for the introduction of hydroxyl group.
Monomer Unit of Formula (IId)
Monomers corresponding to the monomer units of Formula (IId) are represented by following Formula (2d): 
wherein R1 is a hydrogen atom or a methyl group; and R12 is a hydrocarbon group having a tertiary carbon atom at a bonding site with an oxygen atom indicated in the formula,
of which a typical example is the following compound:
[2-25] t-butyl (meth)acrylate (R1xe2x95x90H or CH3, R12=t-butyl group).
Monomer Unit of Formula (IIe)
Monomers corresponding to the monomer units of Formula (IIe) are represented by following Formula (2e): 
wherein R1 is a hydrogen atom or a methyl group; and n denotes an integer from 1 to 3,
of which typical examples are the following compounds:
[2-26] 2-tetrahydropyranyl (meth)acrylate (R1xe2x95x90H or CH3, n=2); and
[2-27] 2-tetrahydrofuranyl (meth)acrylate (R1xe2x95x90H or CH3, n=1)
Monomer Unit of Formula (IIf)
Monomers corresponding to the monomer units of Formula (IIf) are represented by following Formula (2f): 
wherein R1 is a hydrogen atom or a methyl group; and R13, R14 and R15 are the same or different and are each hydrogen atom or a methyl group,
of which typical examples are the following compounds:
[2-28] 3-(meth)acryloyloxy-xcex3-butyrolactone (R1xe2x95x90H or CH3, R13xe2x95x90R14xe2x95x90R15xe2x95x90H);
[2-29] 3-(meth) acryloyloxy-3-methyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R13xe2x95x90CH3, R14xe2x95x90R15xe2x95x90H);
[2-30] 3-(meth)acryloyloxy-4-methyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R13xe2x95x90R15xe2x95x90H, R14xe2x95x90CH3);
[2-31] 3-(meth)acryloyloxy-3,4-dimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R13xe2x95x90R14xe2x95x90CH3, R15xe2x95x90H);
[2-32] 3-(meth)acryloyloxy-4,4-dimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R13xe2x95x90H, R14xe2x95x90R15xe2x95x90CH3); and
[2-33] 3-(meth)acryloyloxy-3,4,4-trimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R13xe2x95x90R14xe2x95x90R15xe2x95x90CH3).
The compounds represented by Formula (2f) can be obtained, for example, in accordance with the following reaction process chart: 
wherein R1, R13, R14, R15 and Rx have the same meanings as defined above.
In the above reaction process chart, the conversion (isomerization) of an xcex1-hydroxy-xcex3-butyrolactone represented by Formula (18) into a xcex2-hydroxy-xcex3-butyrolactone represented by Formula (19) can be performed by dissolving the compound of Formula (18) in water or a solvent, where necessary, with a small amount of an acid such as sulfuric acid or hydrochloric acid. The solvent is not specifically limited, and includes, for example, acetonitrile, acetic acid and ethyl acetate. A reaction temperature is, for example, from about 0xc2x0 C. to about 150xc2x0 C. and preferably from about 20xc2x0 C. to about 100xc2x0 C. The xcex1-hydroxy-xcex3-butyrolactone (18) for use as a raw material can be produced in a similar manner to that in a compound represented by Formula (23) mentioned below. Alternatively, the compound of Formula (19) can be obtained by subjecting the compound of Formula (18) to a reaction (a dehydration reaction) with phosphorus pentoxide to yield a corresponding xcex1,xcex2-unsaturated-xcex3-butyrolactone, allowing this compound to react with a peracid such as hydrogen peroxide or m-chloroperbenzoic acid to epoxidize a double bond, and hydrogenating the same in the presence of a catalyst such as Pdxe2x80x94C. Alternatively, the compound of Formula (19) can be produced by a conventional process for the preparation of a xcex2-hydroxy-xcex3-butyrolactone.
A reaction between the xcex2-hydroxy-xcex3-butyrolactone (19) and the (meth)acrylic acid or its derivative represented by Formula (9) can be performed in a similar manner to the reaction between the compound of Formula (8) and the (meth)acrylic acid or its derivative (9).
Monomer Unit of Formula (IIg)
Monomers corresponding to the monomer units of Formula (IIg) are represented by following Formula (2g): 
wherein R16 is a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or an 2-oxepanyl group,
of which typical examples are the following compounds:
[2-34] 5-t-butoxycarbonylnorbornene (R16=t-butyl group);
[2-35] 5-(2-tetrahydropyranyloxycarbonyl)norbornene (R16=2-tetrahydropyranyl group); and
[2-36] 5-(2-tetrahydrofuranyloxycarbonyl)norbornene (R16=2-tetrahydrofuranyl group).
Monomer Unit of Formula (IIIa)
Monomers corresponding to the monomer units of Formula (IIIa) are represented by following Formula (3a): 
wherein R1 is a hydrogen atom or a methyl group; R17 and R18 are the same or different and are each a hydrogen atom, a hydroxyl group or a carboxyl group; and R19 is a hydroxyl group, an oxo group or a carboxyl group,
of which typical examples include the following compounds:
[3-1] 1-hydroxy-3-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R19xe2x95x90OH, R17xe2x95x90R18xe2x95x90H);
[3-2] 1,3-dihydroxy-5-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R19xe2x95x90R17xe2x95x90OH, R18xe2x95x90H);
[3-3] 1-carboxy-3-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R19xe2x95x90COOH, R17xe2x95x90R18xe2x95x90H);
[3-4] 1,3-dicarboxy-5-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R19xe2x95x90R17xe2x95x90COOH, R18xe2x95x90H);
[3-5] 1-carboxy-3-hydroxy-5-(meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R19xe2x95x90OH, R17xe2x95x90COOH, R18xe2x95x90H);
[3-6] 1-(meth)acryloyloxy-4-oxoadamantane (R1xe2x95x90H or CH3, R19=4-oxo group, R17xe2x95x90R18xe2x95x90H);
[3-7] 3-hydroxy-1-(meth)acryloyloxy-4-oxoadamantane (R1xe2x95x90H or CH3, R19=4-oxo group, R17=3-OH, R18xe2x95x90H); and
[3-8] 7-hydroxy-1-(meth)acryloyloxy-4-oxoadamantane (R1xe2x95x90H or CH3, R19=4-oxo group, R17=7-OH, R18xe2x95x90H).
The compounds represented by Formula (3a) can be obtained, for example, in accordance with the following reaction process chart: 
wherein R1, R17, R18, R19 and Rx have the same meanings as defined above.
In this reaction process chart, a reaction between an 1-adamantanol derivative (20) and the (meth)acrylic acid or its derivative (9) can be performed in a similar manner to the reaction between the 1-adamantanol derivative (8) and the (meth) acrylic acid or its derivative (9). The 1-adamantanol derivative (20) for use as a raw material can be obtained, for example, by introducing a hydroxyl group or a carboxyl group into the adamantane ring of an adamantane compound. The introduction of a hydroxyl group and carboxyl group into the adamantane ring can be performed in the same manner as above.
Monomer Unit of Formula (IIIb)
Monomers constituting the monomer units of Formula (IIIb) are represented by following Formula (3b): 
wherein R1 is a hydrogen atom or a methyl group; and R20, R21, R22, R23 and R24 are the same or different and are each a hydrogen atom or a methyl group,
of which typical examples include the following compounds:
[3-9] 2-(meth)acryloyloxy-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R21xe2x95x90R22R23xe2x95x90R24xe2x95x90H);
[3-10] 2-(meth)acryloyloxy-2-methyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90CH3, R21xe2x95x90R22xe2x95x90R23xe2x95x90R24xe2x95x90H);
[3-11] 2-(meth)acryloyloxy-4,4-dimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R21xe2x95x90R22xe2x95x90H, R23xe2x95x90R24xe2x95x90CH3);
[3-12] 2-(meth)acryloyloxy-2,4,4-trimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R23xe2x95x90R24xe2x95x90CH3, R21xe2x95x90R22xe2x95x90H);
[3-13] 2-(meth)acryloyloxy-3,4,4-trimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R22xe2x95x90H, R21xe2x95x90R23xe2x95x90R24xe2x95x90CH3);
[3-14] 2-(meth)acryloyloxy-2,3,4,4-tetramethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R21xe2x95x90R23xe2x95x90R24xe2x95x90CH3, R22xe2x95x90H);
[3-15] 2-(meth)acryloyloxy-3,3,4-trimethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R24xe2x95x90H, R21xe2x95x90R22R23xe2x95x90CH3);
[3-16] 2-(meth)acryloyloxy-2,3,3,4-tetramethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R21xe2x95x90R22xe2x95x90R23xe2x95x90CH3, R24xe2x95x90H);
[3-17] 2-(meth)acryloyloxy-3,3,4,4-tetramethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90H, R21xe2x95x90R22xe2x95x90R23xe2x95x90R24xe2x95x90CH3); and
[3-18] 2-(meth)acryloyloxy-2,3,3,4,4-pentamethyl-xcex3-butyrolactone (R1xe2x95x90H or CH3, R20xe2x95x90R21xe2x95x90R22xe2x95x90R23xe2x95x90R24xe2x95x90CH3).
The compounds represented by Formula (3b) can be obtained, for example, in accordance with the following reaction process chart: 
wherein Rz is a hydrocarbon group; and R1, R20, R21, R22, R23, R24 and Rx have the same meanings as defined above.
The hydrocarbon group in Rz in the above reaction process chart includes, for example, methyl, ethyl, propyl, s-butyl, t-butyl, vinyl, allyl and other aliphatic hydrocarbon groups (alkyl groups, alkenyl groups or alkynyl groups) each having from about 1 to about 6 carbon atoms; phenyl group, naphthyl group and other aromatic hydrocarbon groups; and cycloalkyl groups and other alicyclic hydrocarbon groups.
A reaction of an xcex1,xcex2-unsaturated carboxylic ester (21) with an alcohol (22) and oxygen is performed in the presence of a N-hydroxyimide catalyst such as N-hydroxyphthalimide, and where necessary, a metallic promoter such as a cobalt compound (e.g., cobalt acetate or acetylacetonatocobalt). The ratio of the xcex1,xcex2-unsaturated carboxylic ester (21) to the alcohol (22) can be appropriately selected depending on the types (e.g., cost and reactivity) of the two compounds. For example, the alcohol (22) may be used in excess (e.g., from about 2 to about 50 times by mole) to the xcex1,xcex2-unsaturated carboxylic ester (21), and vice versa, the xcex1,xcex2-unsaturated carboxylic ester (21) may be used in excess to the alcohol (22). The amount of the N-hydroxyimide catalyst is, for example, from about 0.0001 to about 1 mole and preferably from about 0.001 to about 0.5 mole, relative to 1 mole of the compound that is used in a less amount between the xcex1,xcex2-unsaturated carboxylic ester (21) and the alcohol (22). The amount of metallic promoter is, for example, from about 0.0001 to about 0.7 mole and preferably from about 0.001 to about 0.5 mole, relative to 1 mole of the compound that is used in a less amount between the xcex1,xcex2-unsaturated carboxylic ester (21) and the alcohol (22). Oxygen is often used in excess to the compound that is used in a less amount between the xcex1,xcex2-unsaturated carboxylic ester (21) and the alcohol (22). The reaction is performed in a solvent at a temperature of from about 0xc2x0 C. to about 150xc2x0 C. and preferably from about 30xc2x0 C. to about 100xc2x0 C. at atmospheric pressure or under a pressure (under a load). Such solvents include, but are not limited to, acetic acid and other organic acids, acetonitrile and other nitrites, trifluoromethylbenzene and other halogenated hydrocarbons, and ethyl acetate and other esters.
A reaction between the resulting xcex1-hydroxy-xcex3-butyrolactone derivative (23) and the (meth)acrylic acid or its derivative (9) can be carried out in a similar manner to the reaction between the 1-adamantanol derivative (8) and the (meth)acrylic acid or its derivative (9).
Monomer Unit of Formula (IIIc)
Monomers constituting the monomer units of Formula (IIIc) are represented by following Formula (3c): 
wherein R1 and R25 are the same or different and are each a hydrogen atom or a methyl group,
of which specific examples are the following compounds. These compounds can be prepared by a conventional or known technique.
[3-19] 1-(Meth)acryloyloxyadamantane (R1xe2x95x90H or CH3, R25xe2x95x90H); and
[3-20] 1-(meth)acryloyloxy-3,5-dimethyladamantane (R1xe2x95x90H or CH3, R25xe2x95x90CH3).
Monomer Unit of Formula (IIId)
Monomers constituting the monomer units of Formula (IIId) are represented by the following Formula (3d): 
wherein R1 is a hydrogen atom or a methyl group; R26 is a tricyclo[5.2.1.02,6]decylmethyl group, a tetracyclo[4.4.0.12,5.17,10]dodecylmethyl group, a norbornyl group, an isobornyl group or a 2-norbornylmethyl group; and
R27 is a substituent of R26 and is a hydrogen atom, a hydroxyl group, a hydroxymethyl group, a carboxyl group or a xe2x80x94COOR28 group, where R28 is a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or an 2-oxepanyl group, of which typical examples include the following compounds. A known or conventional process can yield these compounds, such as a process in which a corresponding alcohol (HOxe2x80x94R26xe2x80x94R27) and the (meth) acrylic acid or its derivative (9) are subjected to an esterification reaction.
[3-21] 8-Hydroxymethyl-4-(meth)acryloyloxymethyltricyclo[5.2.1.02,6]decane;
[3-22] 4-hydroxymethyl-8-(meth)acryloyloxymethyltricyclo[5.2.1.02,6]decane;
[3-23] 4-(meth)acryloyloxymethyltetracyclo[4.4.0.12,5.17,10]dodecane;
[3-24] 2-(meth)acryloyloxynorbornane;
[3-25] 2-(meth)acryloyloxyisobornane; and
[3-26] 2-(meth)acryloyloxymethylnorbornane. 
Monomer Unit of Formula (IIIe)
Monomers constituting the monomer units of Formula (IIIe) are represented by the following Formula (3e): 
wherein R1 has the same meaning as defined above,
of which specific examples are the following compounds:
[3-29] (meth)acrylic acid (R1xe2x95x90H or CH3).
Monomer Unit of Formula (IIIf)
A monomer constituting the monomer unit of Formula (IIIf) is the following compound represented by following Formula (3f): 
[3-27] maleic anhydride.
Monomer Unit of Formula (IIIg)
A monomer constituting the monomer unit of Formula (IIIg) is the following compound represented by following Formula (3g): 
[3-28] norbornene.
A photoresist resin composition of the present invention comprises the invented polymeric compound for photoresist and a light-activatable acid generator.
As the light-activatable acid generator, known or conventional compounds that can efficiently generate an acid upon exposure to light can be employed. Such compounds include, but are not limited to, diazonium salts, iodonium salts (e.g., diphenyliodonium hexafluorophosphate), sulfonium salts (e.g., triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium methanesulfonate), sulfonates [e.g., 1-phenyl-1-(4-methylphenyl)sulfonyloxy-1-benzoylmethane, 1,2,3-trisulfonyloxymethylbenzene, 1,3-dinitro-2-(4-phenylsulfonyloxymethyl)benzene, and 1-phenyl-1-(4-methylphenylsulfonyloxymethyl)-1-hydroxy-1-b enzoylmethane], oxathiazol derivatives, s-triazine derivatives, disulfone derivatives (e.g., diphenyldisulfone), imide compounds, oxime sulfonates, diazonaphthoquinone, and benzoin tosylate. Each of these light-activatable acid generators can be used alone or in combination.
The amount of the light-activatable acid generator can be appropriately selected depending on the strength of an acid generated by light irradiation or the proportion of each monomer unit in the polymeric compound, and is, for example, from about 0.1 to about 30 parts by weight, preferably from about 1 to about 25 parts by weight, and more preferably from about 2 to about 20 parts by weight, relative to 100 parts by weight of the polymeric compound.
The photoresist resin composition may further comprise additional components. Such additional components include, but are not limited to, alkali-soluble resins (e.g., novolak resins, phenol resins, imide resins, and carboxyl-group-containing resins) and other alkali-soluble components, coloring agents (e.g., dyestuffs), and organic solvents (e.g., hydrocarbons, halogenated hydrocarbons, alcohols, esters, amides, ketones, ethers, Cellosolves, Carbitols, glycol ether esters, and mixtures of these solvents).
The photoresist resin composition is applied onto a base or a substrate and is dried, and the resulting film (resist film) is exposed to light through a predetermined mask (or is further subjected to post-exposure baking) to form a latent image pattern, and the film is then developed to thereby highly precisely yield a fine pattern.
Such bases or substrates include, for example, silicon wafers, metals, plastics, glasses and ceramics. The photoresist resin composition can be applied using a conventional application means such as a spin coater, a dip coater and a roller coater. The applied film has a thickness of, for example, from about 0.1 to about 20 xcexcm, and preferably from about 0.3 to about 2 xcexcm.
Light rays with different wavelengths, such as ultraviolet rays and X-rays, can be used for exposure operation. For example, g-line, i-line, and excimer laser (e.g., XeCl, KrF, KrCl, ArF, or ArCl) are usually used for semiconductor resists. An exposure energy is, for example, from about 1 to about 1000 mJ/cm2, and preferably from about 10 to about 500 mJ/cm2.
An acid is generated from the light-activatable acid generator by action of light irradiation and immediately deprotects the protective group (leaving group) of the carboxyl group of the polymeric compound. Thus, a carboxyl group that contributes to solubilized resin is formed. Subsequent development with water or an alkali developer can therefore precisely form a predetermined pattern.
The invented polymeric compounds for photoresist each have a monomer unit having an alicyclic skeleton of a specific structure carrying a lactone ring, can satisfactorily adhere to substrates and are resistant to swelling in a developer. Additionally, by using the monomer unit with other monomer units of specific structures, the resulting polymeric compounds can exhibit well-balanced adhesion to substrates, transparency, alkali-solubility and etching resistance.
The invented method of manufacturing a semiconductor uses the polymeric compound having the satisfactory characteristics as a resist and can highly precisely produce fine patterns.